It’s been exactly four years since the Arab Spring forever changed Egypt. The world watched it all unfold on television as, for more than two weeks, massive crowds gathered in Cairo’s Tahrir Square, calling for President Hosni Mubarak to step down. 

On Feb. 11, 2011, they got their wish. Mubarak handed over power to the military, and the changes began. But since then, Egypt seems to have gone from one tyranny to another. Clashes have persisted. Protesters have been arrested.

So how did we get to where we are today? And is there an end in sight? That’s the subject of Middle East reporter Thanassis Cambanis's new book, "Once Upon a Revolution."